Years after settling what appeared to be an on-air feud, David Letterman and Oprah Winfrey have reunited again for an episode of her OWN interview series "Oprah's Next Chapter."

The interview was carried out at Letterman's alma mater, Ball State University in Muncie, Indiana. He had grown up in the state and moved to Los Angeles to become a comedian. He and Leno met in 1975 and performed at the same clubs. Letterman got his big break by performing on NBC's "Tonight Show" in 1978. He began to host NBC's "Late Night" talk show, which airs afterwards, in 1982.

The relationship between Letterman and Winfrey had been strained for years, starting more than 15 years ago. At the 1995 Academy Awards, which Letterman hosted, a joke that featured him pretending to introduce Winfrey to actress Uma Thurman as "Oprah, Uma. Uma, Oprah ... Have you kids met Keanu?" fell flat. Winfrey and Thurman, who were sitting in the audience, laughed politely.

Winfrey then rejected offers to appear on "Late Night." In 1993, Winfrey told Time magazine that while she had appeared on the program twice, she felt that during both times, "I was sort of like the butt of [Letterman]'s jokes. I felt completely uncomfortable sitting in that chair, and I vowed I would not ever put myself in that position again."

Winfrey also added that she had a "great deal of respect for his talent." Meanwhile, Letterman often poked fun at the veteran daytime talk show host and had a running gag on his show called the "Oprah Log," which would show him talking about his goal of appearing on Winfrey's program.

The two appeared to reconcile in 2005, when she was a guest on the "Late Show." Letterman finally appeared on "The Oprah Winfrey Show" in 2007. Winfrey said at the time that her relationship with him had warmed.

Earlier that year, he and Winfrey appeared together in a commercial for his show that aired during the Super Bowl. They reunited on a similar television ad that also featured Leno.

In May 2011, Winfrey's talk series "The Oprah Winfrey Show" ended. Letterman joked that he was "more than upset" that he was not invited to the taping of the final episode, saying on his program: "I spent the last 12 to 15 years kissing up to Oprah. Every day I get out of bed and I think, 'What can I do to suck up to Oprah? Guess who wasn't invited? Thank you very much, Oprah."

Letterman and Winfrey discuss the so-called feud during their "Oprah's Next Chapter" interview, which airs on OWN on January 6 at 9 p.m. ET. This marks the first time Winfrey reveals to Letterman the "true reason" behind it, the cable channel said in a statement to OTRC.com.

He also talks about how he weathered a sex scandal that threatened his marriage, his battle with depression and his relationships with the late Johnny Carson of "The Tonight Show," and Jay Leno, who took over his role as host in 1992 and who remains a rival of Letterman, who had expected to get the job.

Letterman has spoken about these topics before. In 2009, Letterman admitted publicly that he had had sexual affairs with women who worked on the "Late Show" and said he would try to work things out with his wife Regina, the mother of his son, Harry. The talk show host added that he was the victim of an extortion plot.

A producer for the CBS show "48 Hours" was indicted for attempted grand larceny and accused of trying to blackmail Letterman by threatening to write a screenplay and a book about the affairs if the host did not pay him $2 million. He pleaded guilty and was sentenced to six months in jail and was released after four.

In a 2011 interview with ABC's Barbara Walters, Letterman said he has "dabbled" in depression and received "medicinal help" for it, adding: "There's a difference in being sad and being blue and being depressed and being chemically or clinically depressed. I do know the difference between those and it's horrifying."